Drying oil



Aug. 8, 1950 1 R. A. CARLETON DRYING OIL Filed March 2, 1943 5Sheets-Sheet 1 Aug. 8, 1950 R. A. CARLETON DRYING OIL 5 Sheets-Sheet 2Filed March 2, 1943 alH h l l l lh l l l l l l l lwl l l I I I H Hu l ll l m l l r INVENTOR Aug. 8, 1950 R. A. CARLETON DRYING OIL 5Sheets-Sheet 3 Filed March 2, 1943 INVENTOR 444 ail W14 Aug. 8, 1950 R.A. CARLETON DRYING OIL 5 Sheets-Sheet 4 Filed March 2, 1943 INVENTORAug. 8, 1950 R. A. CARLETON DRYING OIL 5 Sheets-Sheet 5 Filed March 2,1943 14 WMM4%%' M W rn sq Patented Aug. 8, 1950 when i ,Y' lB i O RobertA; Carleton, Maniaroneck, 1.

This invention'relates c a-methodorprpduc ing drying oils ofimproved'drying' and film forrn-- ing properties, from drying oils {ornon-conjugate type. v r H y invention primarily re ates to which areunited by double bonds',by which treat ment new doublebonds areintroduce'd and'rear l the carbon chain rangement" of. double bonds I cI c to give a conjugate rather than a non-conjugate structure iseitected. It is to of double bonds intodete rminate posmbns m the volvesbothf an increasein t double bonds linking "partied bon atoms of thecarbon chain, tioning of these carbonatonis in nsaturate re and in suchnos bonds are in conjugate relation." My invention concerns itself knownfact that in dryingbils, the rapidity with which they dry and thehardness ofthe film which they produce is affected not only by thewhich: saturation of the oil, or bonds which it contains thearrangementof the unsaturated lihltages 'or' I the oil mommies- It'is'well understood that e'ach dryingoil' isflco'rnposed double carbonbonds, in

of a varying number or"components-which;m

instances present great difir'ence's; inthe order of their unsaturation,and in-the arrangement or their double carbon bonds. L The above i'sto'be' taken generally 'as referring toeachcommerci'al drying orsemi-drying oil;

bean oil, etc., and'in its 'relation specifically 'to-the order of.unsaturation and the order otconjuga tion is to be taken also asrelating'to 'the-individual components offthe oils, such as'thej glyc'erides' of linoleic acid; and the glycerides of nn'pieme acid.

drying oil product which treatment to which it has beensubj'ected 'iscom: posed in substantial entirety"'of"desired 'corn which is effected 2and treatments in a-in'anner provement 'in' the'properties of thedr'yin'groil prod-- uct whichisrecoveredand in a mannertoobtain atreatment of non conjugate type glyceride oils-containing large amountsof glycei'id'es having 18 or m re; atoms in the'carb'on' chain, at1easttwojpairs -of=v I be understood fur ther that my invention involvestrfeintroductipir' carbon chain of the oil'inolecul'es; and that'i't inH thcafbonchain that approximately all the 'introduced double:

'with'the weir" umber of double-carbon" V but that thosedesirablepropertiesof the drying on are arrested 'greatly by such as linseed oil;soya My invention concerns'itself alsowith a finished by virtue or the"total in dete'rminate order the a physical and chemical 1 changesgiv'ing the desired product.

1 As is 'well-known,China-Wood oil maybe taken as exemplifying dryingoils having most of their a; double bondsin conjugate relation, anotherand less known member of'the class being oiticicaoil.

While the total unsaturation of China-wood-oil, as represente'd by itsiodine absorptionfindex, is

substantially less than the total unsaturation oi linseed oil or perilla'oil'fChina-wood'oil dries much fmore' rapidly than the rnore u'i'saturate oils the unsaturated glycerides of 'whiehpresent as an averageno substantial conjugation." Thus, China-wood oil is compes'ea arge1y'or the highly reactive glyceride of elostearicecid, in whichsubstantially all the double 'Lbo'rids-"-present are in conjugaterelation. As is'well k'nown, that oil polymerizes or gels atequal'temperatures many times faster than the more unsaturate butnon-conjugate and relatively lessreactive linseed oil. As noted, thereis substantial difference in the type of film formed by conjugate typeoils and the non-conjugate type oils because the are" characterized bythrough drying to give hard and highly resistant coatings, whereas thefilms of'non conjugate oils dry from the surface, so that the underlyingregions of the film dry slowly, andthe film does not have the hardnessand resistance ofa film composed of the conjugate type "Itfis generallyconsidered that the non-conjugate type glyc'erid'e oils owe their dryingproperties chiefly to their inclusion of unsaturate linoleic acidglyercides having two double carbon bonds inthe 9-10 and 12-13 positionsand an iodine value of about glycerides having three double carbonbonds-in the 9-10, 12-13, and 15-16 positions, and an iodinevalueflofabout 274.. In addition the oils containjglycerides of oleic acid and ofsaturate acids, having little or no drying power. The glyceride of oleicacid .has one double carbon bondin the-9-1O position, and has an iodinevalue do those'otherand non conjugateoils, and has the ability to formfilms conjugate oils form films which 181, and to linolenic acid,

As has been above indicated, the proportions of the several saturate andunsaturate fatty acid glycerides occur in the various oils in greatlyvaried proportions, to form mixed triglycerides. Certain oils, such ascotton seed oil and corn oil, while containing substantial amounts oflinoleic acid glycerides, also contain a large proportion of saturatefatty acid glycerides and of oleic acid glyceride. These oils, of whichI may take cotton seed oil and corn oil as exemplary, are not,therefore, commonly considered to be drying oils. These examples of suchoils as have iodine values over 100, may be used alone or in mixtures asthe starting oil for my process.

My present invention involves the discovery that by hydroxylating andthen condensively dehydroxylating unsaturate non-conjugate glycerides offatty acids there are introduced in the carbon chains of the oilmolecules an increased number of double carbon bonds in determinatepositions and in conjugate relation. I have discovered that thishydroxylation and attendant condensive dehydroxylation, withintroduction of double carbon bonds in determinate conjugate relationmay be effected selectively, to impart to the, oil increased tendencyreadily to polymerize which is of measured order.

Concretely I have discovered that the reactivity of fatty acidglycerides having 18 or more carbon atoms and two or more doublebondlinkages in the carbon chain may be greatly increased byhydroxylation followed by condensive dehydroxylation to introduce newdouble carbon bonds and to increase conjugation in the carbon chains ofthe oil molecules, and that the hydroxylation and consequently thedehydroxylation may be selective as to the number and positionsof-theunsaturate carbon atoms which are, involved. This involves thefurther discovery that the determinate positions in whichdehydroxylation based upon precedent hydroxylation is effected in dryingoils of that type are such as to give maxi: mum effectiveness.inincreased reactivity to the increased unsaturation and the conjugationwhich has been introduced.

The hydroxylgroup addition to the unsaturate carbon atoms, whichcomprises the first step in my novel process, is effected by reaction ofthe oil with oxygen inthe presence. of Water, and any suitable andconvenient reagentsand procedure for so doing may be employed.

In exploring the mechanism, I have found that epoxide formation andhydroxyl. addition to the unsaturate carbon atoms in the glyceridemolecules may be accomplished in various ways. One manner ofaccomplishing this is totreat the starting oil with air or otheroxygen-containing gas, with or without the use of oxidation catalysts,and effecting the hydroxylation predicated upon epoxide formation byconducting'the oxidation procedure in thepresence of steam or water, sothat cpcxide formation is accompanied-imme diately by hydration. Anotherprocedure, by; which hydroxyl addition is accomplished -is.;.b'y,treating the oil withwater solutions of compounds Which readily give upoxygen, such for ex e a ot sium rm n an t i" hy r e peroxide. A stillfurther example of procedure for effecting hydroxyl addition 'atunsaturate carbon atoms of the glycerides is to effect epoxide formationimmediately resulting in hydroxylation, by reacting and decomposing aWater solution of oxygen-containing compounds such as sodium carbonatewith a reagent therefor such as gaseous chlorine, with subsequentliberation of free oxygen, which reacts with the unsaturate carbonatoms'present to add hydroxyl groups thereto. It is possible also tocombine these procedures as by treating the oil with air and with awater solution of an oxygenating compounds, such as potassiumpermanganate.

The above recited procedures are to be taken as illustrative oftreatment by which the fact of hydroxylation in the oil molecules may beattained, and not as limitations upon my invention. It is to beunderstood that hydroxylation of itself serves to decrease rather thanto increase the unsaturation and reactivity of the oil. When, however,the hydroxylation is associated or combined with condensivedehydroxylation a marked increase in unsaturation and reactivity of thetreated over the untreated oil is accomplished.

-ll ehydroxylation is effected by condensation between the addedhydroxyl groups and hydrogen atoms of the original molecular structureunder the influence of heat and preferably also withacondensivedehydroxylation catalyst and under substantially. anhydrousconditions. Assuming that dehydroxylation is effectively performed, theincreased, unsaturation and the conjunction effected in the glyceridesof the oils depends upon the order of hydroxylation which has beeneffected in them. Consequently, the order in which unsaturation isincreased and conjugation created in the treated; glycerides iscontrollable by seleetivity in the precedent hydroxylation.

Selectivity in the treatment of. the. oil to. increase its unsaturationand conjugation is an important consideration. If we consider linseedoil as-thestarting material for my treatment, it has been above notedthat the composition of such oil is approximately 24% linolenic acidglyceride, 62% linoleic acid glyceride, 5% oleic acidglyceride, and 9%saturate acid glycerides. Linoleic acid has in its carbon chain twodouble carbon bondsin the 9-10 and 12-13 positions. If then we considerthat the acid is completely hydrpxylated to form tetrahydroxystearicacid and then issubjectedto condensive dehydroxylation, four, oftheoriginal atoms of hydrogen are removed from the molecule and fourconjugated double carbon bonds are introduced in the 7-8, 9-10, 11-12,and 13-14 positions, Similarly linolenicacid has in its carbon chaindouble bonds in the 9-10, 12-13, and 15-16 positions. When there iscomplete hydroxyl group addition to form hexahydroxystearic acid,followed by condensive dehydroxylation, the result is to remove six ofthe. original hydrogen atoms and to introduce double bonds in the 6-7,8-9, 10-11, 12-13, 14-15, and l6. l 7.positions. Mechanismof acondensive dehydroxylation reaction is rather complex, and notcompletely understood. In view, however, of theresultsattained, it isquite probable that due to. strains setup in the molecule by therelatively high reacting temperature and atomic recombinations, there.is first'a migration of the relatively mobile hydrogen atoms withresultingshift in position of the active carbon atoms, to permitcondensation between the added hydroxyl group and an adjacent hydrogenatom to form the above indicateddouble bond arrangement, withoutsubstantial formation of objectionable ring compounds.

-I- have found that because of an inherent selectivity, orv differencein the degree of reactivity toward epoxidation exhibited by the severalunsaturate carbon atomsin the oil molecule, depending upon. theirrelative. position in the carbonchain, and by the quantitive andselective regulation of the variables affecting the hydroxyl groupaddition to the unsaturated carbon: atoms, the startingoil may betreated by the present invention to have a lesser or greater determinatedegree of unsaturation and conjugation with consequent variation in itsheat-reactivity within the aforesaid range. It may be here noted thatthe position of the unsaturate' carbon atoms in the molecules of adrying oil has a great influence on the reactivity of the oil;Unsaturation, and more particularly conjugate unsaturation, tends moregreatly to heat reactivity and oxygenreactivity of the oil the closer itis to 'the glycerol radical of the oil molecule. It is animportantaspect of my process, as will hereinafter appear more specifically, thatin it unsaturation, and unsaturation in conjugate relation, isintroduced directly and permanently in determinate positions and thatsuch positions are favorable to high reactivity of the product oil.

The initial factor in my process is the' ability of unsaturate carbonatoms to react-additively with oxygen to form epoxide, which in thepresence of water immediately hydrates to form' a hydroxyl groupaddition. I have foundfurther that when two or more pairs of such carbonatoms are present the position of the carbon atoms solihked in thecarbon. chain greatly influence's'their relative reactivity with oxygen.Thus if linoleic acid glyceride be considered, the carbon atoms inthe9-10 position require greater stimulus to cause their reaction withoxygen than is required by the carbon atoms in the. 1213"-positi0n. Inlinolenic acid glyceride the carbon atoms in the 15-16 position in likemanner have greater reactivity than the carbon atoms inthe 9-10position, and they in turn have greater reactivity with oxygen than thecarbon atoms in the 12-13 position.

individual operation, the intent to effect selec-.

tivity-being present and procedural guides of general sort being had.The quantity of oxygen which may be rendered available from theoxygen-supplying substance used in the process may be taken astheprimary guide with respect to the desired theoretical epoxideformation and hydroxyl addition to the. oil molecule. The supply ofwater and its contact with the oil involved in hydroxylation should beample to effect substantially complete and immediate hydration of theepoxide addition. The efliciency of. the procedure by which epoxideformation is effected may then be considered,'and thisiinvolves asvariables the activity of the oxygen-supplying reagent, thetime-temperature and pressure factors, the quantity and efiectiveness=of the oxidation catalyst if such catalyst be'used, and theeffectiveness of contact between the oil molecules and the source ofoxygen.

In all the important non-conjugate drying andsemi-drying oils thepreponderant fatty acid glycerides are the linoleic'acid glyceridehaving 18 carbon atoms and two points of unsaturation in its carbonchain and linolenic acid glyceride having 18 carbon atoms and threepoints of unsaturation in its carbon chain. It may be stated broadlythat the response of any starting oil, or mixture of starting oils, tomy process corresponds closely to the quantity of unsaturates of thatsort which it contains. in the practice of my invention it istherefor'e'a simple matter to adjust'the'variables ;in con-.-,;

The exercise of selectivity in the hydroxylation.

In obtaining selectivity 6 oil.

to stimulate'the mechanism by. which epoxidation occurs and' thehydroxyl groups are added to: When it is'deemed expedient the carbonatoms. to accelerate theactivityof the oxygen-supplying medium ineffecting hydroxylation, epoxidation may be promotedby adding to the oilsubjected to treatment a suitable quantity of well-known oxidationcatalysts including the compounds of oxidizing'metals used'as dryers incoating compositions.

Good oil-oxygen contact is important from the view point of selectivityand from the view point of obtaining the desired orderof treatment inthe entire volume of oil treated: If highoiloxygen contact efficiency isobtained, regulation of the other variables of the process to obtainapproximate uniformity" and selectivity .in -thechanges appearingin'theproduct oil is facilitated.

Thus if the contact factor approaches maximum eihciency, the time oftreatment'is shortened, and the quantity of oxygen rendered available inreaction with the oil approaches closer to the quantity supplied'by theoxygen-containing reagent in effecting the desired theoreticalepoxide-formation and hydroxylation.

and such checking is facilitated ina continuous operation in which'fully treated samples re-.

peatedly may be taken, in which there is substantialuniformitythroughoutthe body of the oil being treated, and in which the variablesare particularly well under control. Thus thedecrease in unsaturationcaused by the hydroxylation may be determined by well-known and usualtests for change in iodine and hydroxyl. value. By observing the resultsof such tests appropriate changes in the variablesv involved in thehydroxylation procedure may be'made to deliver for condensivedehydroxylation'oil which-has been hydroxylated to the extent desired. I

The subsequent step of condensive dehydrogenation, which as iswell-known involves the removal of a hydrogen atom from the oil moleculeto combine with a hydroxyl group to form water, is effected primarily byheat. This is'illustrated by prior practice-in the dehydration of castoroil in which one hydroxyl group initially ispresent; 1 I

The time-temperature variable in thecondensive dehydroxylation quitecommonly is decreased by the use of a dehydrating catalyst. 'A typicalactivating dehydration treatment for castor oil is to hold the oil at atemperature of about 400.F. to 500 F. for 2 to 3 hours, using asubstantial quantity up to .4% or .5% the weight of .the oil of asuitable dehydrating catalyst, such as the salt of a non-oxidizing acid.Dehydrated castor oil is, however, much less heat-reactive than myproduct oils. Thus China-wood oil under standard gelatin test conditionusually polymerizes to as ubstantially dry gel in 10 to 12 minutes ataformity with altered compositionsof the starting.

in my process it is notnecessar y catalytically 2; @117; see

7 stantially dry gel.in.3i to: 5. minutes at atemperature of 600 F.

The condensive: dehydroxylation stage of my process thus-presents a.problem which is. not met in the treatmentof castor oil. Because of thehigh' heatireactivity of the oil' which is subjected successively tohydroxylationv andv to condensive dehydroxyla'tion in accordance with myinvention, there is a tendency for the oil strongly to polymerizeimmediately upon dehydration. If then this stage of the process becarried on in a .relatively large mass: of the oil, thedehydrated oiltends rapidly to polymerize and to pass to a stageof high voscosity orgelation. before it can be cooled belowits polymerization temperature.

I employ a..flash dehydration procedure, by

whiclr the hydroxylatedi oil is condensively' dehydrated with:relatively slight increase in its viscosity. Desirably such flashdehydration is so conductedthat water from the reaction is removedfrom'the. oil substantially as it is formed,

and it dependsv primarily upon. raising the oil very. rapidly,.insubstantially less than one minute, to a temperature much higher thancommonly employed in dehydrating castor oil, for example, a temperatureof from about 500 F. to 700 F. and. even higher, and upon substantialcompletion of the reaction immediately cooling the oil. below its activepolymerization temperature:. In such procedurethe oil is so presentedfor heating, as in a thin film, that its heat-absorption is very rapid.and the oil moves rapidly through the zone in which it is treated.

Exemplary apparatus in which the method of my invention in itsvariantembodiments may be practiced is shown inthe accompanying drawings, itbeing understood that the apparatus herein shown is illustrative only ofmany forms and types of apparatus which conceivably may be employedwhile conforming to the method of my invention.

In the drawings:

Fig. Ia is a diagrammatic view showing one Fig. II is a cross-sectionalview through the hydroxylation reactor shown in Fig; Ia taken in theplane of the section line II-II of Fig. Ia, and showing in detail one ofthe elements of, the said hydroxylation reactor which are organized toprovide contact between the oil subjected to treatment and the reagent,or reagents, with which it is treated.

Fig. III is a vertical sectional View through the contact element ofFig. II taken in the plane of the section line III-'-III of Fig. II.

Fig. IV is a fragmentary vertical sectional detail view taken throughthe upper region of the dehydration reactor shown in r Ib, the portionof the reactor shown being embraced by the bracket line IV-IV ofv Fig.Ib.

Fig. V'is a fragmentary vertical sectional detail View taken through thedehydration reactor of Fig. Ib in a region intermediate the height ofthe reactor, and embraced by the bracket line V'-V of Fi lb.

Fig. VIis a fragmentary vertical sectional detail view taken through thelower region of the dehydration reactor shown in Fig. Ib, embraced bythe bracketline VIVI of Fig. lb, and showing connections to the lowerregion of the dehydration reactor.

Fig. VII is a diagrammatic view of modified hydroxylat-ion apparatus,which maybe. utilized in place ct -the apparatus shown-in Fig. Ia inoperative: association with suitable dehydrogenation apparatus, suchsuitable, dehydrogenation apparatus being: exemplified: by that shownin- Fig.1!) of the: drawings.

Referring initially to-Fig. Ia and to Figs. II and III: of the"drawings; reference numeral I designates'arr; oil. feed pump which, byway of inlet connection: 2. supplies oil for treatment tohydroxylatingtreactor' 3. A pump 4 supplieswater, which: may be ifdesired a reactive water solution, and which preferably is. mildlyalkaline, to the reactor 3zby way ofan. inlet. 5.

Primarilyconsidered, reactor 3ris a cylindrical.

columnar: vessel which preferably is constructed of metal resistant. to;the corrosive action'of the materials: contained by it during theprogress of the reaction, and isof.- suitable: cross-sectional area andheight. to maintain continuously flowing streams of oil undergoingtreatment and treating reagents: for the oil at suitable reaction.temperatures, for suitable periods of time to effectthe:desiredhydroxylation of the oil'. R'eactor 3- is provided. with aplurality of contact, or

reaction, trays 6' arranged. at spaced intervals.

through'outits height and purposed' to effect intimate contactibetweenthe oil: subjected to treatment and the reagent, or reagents, with whichit is treated;

Reaction" trays 65, as is: shown in detail in. Figs. II and IIIv of. thedrawings; comprise each an upper plate i and a lower: plate 8, spacedapart to forma temperature controlling jacket space 9, provided withinlet. connections litand outlet connections H, for: the supply; ofheating and cooling medium, and. with circulationedirecting baflles l2.A.plurality of bubble caps I3, which are preferably as shown ofrectangular type, and which have closely spaced narrow slots M adjacenttheir loweredges', are supported a suitable distance above plate 1 andenclose the discharge ends of. vapor ducts 15, the lower portions ofwhich pass in-vapor tight manner through jacket spaces 9, and which havetheir. upper openings I 6 in discharge relation with the upper regionsof the: chambers within the bubble caps I3; Interconnection, or down,pipes ll" provide for the flow of liquid from the trays 5 to successivelower trays of? the system; 'Ifhese down pipes I'l' have their upper:intake ends it outside the bubble caps of" the several? trays with whichthey are associated, and positioned a suitable height above the plate l?of each of the trays, to maintain a determinate: depth; of' the liquidflowing over the trays; Thelower outlet ends It of the down pipes I? aresealed'iagainst vapor fiow by submergence an adequate distance in. theliquid of the tray 6 lying next. below" the tray from which theyprovide'overflowconnection.

Speaking'in' terms of' my method, continuously flowing streamsof. oilsubjected to treatment and oxidizing and hydrating reagents introducedre spectively by way of inlets 2 and 5 are supplied tothe uppermost ofthe reaction trays 6 by supply connections 20 and 2!, which dischargeimmediately above the upper surface l of the uppermost trays t, at thespace 22 outside bubble caps rs.

This oil surrounds and moves between bubble caps l3 in a sinuous manner,being drawn oif by way'of down pipe I"! at a level which is a suitableheight, such asabout 1%", above plate I. In accordance with usualprocedure, the inlet E8 of down pipe: [1' is: remote from the openingsof supply. connections oxidizing agent, additional 'tinuously, partbeing drawn by way of connection 20 and 2 l thus tocause movement of theoil past the several bubble caps l3 of the tray. In each of theunderlying trays, the discharge end of down pipe I! leading from thetray next above takes the place ofsupply connections 20 and 2|, butotherwise the arrangement is identical. hhhh A The oil subjected totreatmentthuspasses progressively downward through the reactor, and. inits passage encounters an upwardly rising gaseous oxygen-containingmedium, preferably air, which is preheated to a suitable determinatehydroxylating reaction temperature, such as a temperature from about 130F. to 250 F., and which is supplied at a rate suitable for eiiectinghydroxylation in desired order. I

Such gaseous oxygen-containing I medium, which will be hereinafterspoken of illustratively as air, enters space 24 in reactor 3, at inlet23, and passes by way of vapor ducts I5 into bubble caps 13, from whichit issues into the surround- .ing oil on the several plates 1, in theform of finely-divided bubbles, by way of slots I4 in,the bubble caps.The air thus intimately contacts and agitates the stream of oil passingover the several reaction trays 6, and intimately, mixes with the oil inreactive contact therewith. The residual air separating from the oil inthe uppermost reaction tray 6 passes from the reactor by way of vapordischarge connection 25.

The air thus brought into contact with the oil streams passin overtrays'fi serves the dual purpose of agitating the oil and mixing it withany to the air, which may be used in this step of the process, and alsosupplies oxygen for reaction at unsaturatecarbon atoms of the oil, toeffect epoxide addition thereto. In this connection, it should beexplained .that the water supplied at inlet 5, which may be merelymildly alkaline or may be a, solution of a suitable reagent or catalyst,mixes with theoil in the uppermost of the trays 6, and passing with theoil to successively lower trays in the series throughout the height ofthe reactor, is maintained in a condition of intimate admixture with theoil by the agitation. provided by .the air streams which are passedtherethrough. This water is, as has been explained, necessary to formhydroxyl group additions by hydration at the points of epoxideformation. After passing over successive trays 6, the oil and water aredischarged by a final down pipe 26-to region 21 at the base of thereactor 3, where-it separates .into a lower aqueous body and an upperbody of oil. An oil-water interface level regulator 28 of usualconstruction is provided, and operates in association with pump 4, andpump-flow regulator valve 29, to draw off the aqueous layer from chamber"21 and thus to maintain an approximately constant level of theoil-water interface 30. I is in part recycled conofi by way ofconnection 31 and a fresh'supply being introduced 32 under the influenceof pump 4. This is of importance, if the water con- The water desirablytent be associated with a suitable oxygen-supplying reagent, such forexample as potassium permanganate or hydrogen peroxide, because itprovides for the addition of fresh solution of appropriate concentrationwithout wholly drawing oil the solution which has passed through thereactor. If so desired, however all the used aqueous solution may bewithdrawn and fresh solution supplied. As water is drawn off byway;oi-draw-off connection 3|, pump 4 maintains the :valve 3.6.,- to thelower. tray.

pres ure; u stant l entrainmentby-way; of 'vapor outlet 25.

"The preferred temperature. at which .the .hy-

droxylation iseffectedwilldepend upon the kind and condition of vthe.oil, andother operating variablesp but in generalthe reactingtemperature is -ashighas; may beLused without effecting substantialepoxide::de'Compositiomand @the formation .Df: fiXBda'OXi-dfiti-OHproducts. in the oil. As above noted the preferred temperatures forhydroxylation lies within the approximate range of. 130. .to 250%Etu-Theoil may be subjected to difierent-rates orvintensity ofireaction as itprogresses through the reactor,- .by maintaining the oilwhilepassing-over. different pairs of reacting .=:trays, or;different:individual-trays, at determinate difieren-t ;temperatures.--.

Theetemperaturezicontrol :i the apparatus is obtainablezbyzsupplying, atemperature regulating ifiuid to thejacket spaces :9 in eachof thereaction .traysxfil-uAsshown,sthese jacket spaces are in communication.witha source of; heating fluid, isuch as'jhot waterior, steam, asibyway of connecl".ion*.3,4,--.and.with aisource of cooling water as by wayof;connection-35uziJThe supply of both such temperature controllingmediais under the con- -.trol of a temperatureregulating valve 35,having a heat-sensitive. element l -31 subjectedto the in 'fluen-ce of:the temperature .of material flowing over the: aerating, .or' reaction,trays. As shown, -the u-traysiare connected in pairs, heating andcoolingimediabeing supplied byway of regulating of each'pair of branchinlet connectio lfim andyto the jacket space of the traynext-above bywaysof connection If). 0b-

-viously th e temperature regulating means maybe,,modifieduindependently: to regulate the term peraturein each suchtray. Branch outlet connectionsll, I; lead fromjthe upper memberv ofeach ;.pair. rpf-,.trays -'to alcommion discharge line I la forheatingandcoolingufiuidsw v a.

v By connection, .Qf. such; sort, heating. or cooling iluidis:supplieduto maintain each-region of the reactor; 3 at thedesiredtemperature to which -the ,..automati;cgycontrol, organization isset, or

which itisconstrncted tomaintain. ,It may here be noted thatthejepox1dation reaction is strongly exothermic.-. v

. PIBSSHITBfWithi- -the reactorfmay, if desired, be

icontrol led,byj comniunicatioii with sources of supe tm spheri and :suatmospher c p ssur In'the event water one. water solution of anoxidizing reagent isomittedand steamis supplied by wayof;steaminletconnection20B and. utilized as the sole; hydrating; ;means,the interior of reactor ;3 is preferably maintained at a suitablereduced ,to avoid condensation of @thest a y- Efor sxamp ei wh n ef c gh droxylating reaction to;the-o i1 atv a temperature .qtg E. ,with theuse oi steam, thereactor woulderably b ma nt in any Suitable 1'neans,--at; a press ure of about 20. inches of mer- ZG TX-w 3 191 oth r; nh rpr s in ma circumstances, superatmoa be ,usedto increasethesoluhydrating-mediumin the oilv bil ty; m se an ")1; -;have:difsco,vered that the use of steam tends ,to renderv the-operation .of thehydroxylation reaction more selective'with respect to the points ofunsaturation in the molecule whichare attacked. This is apparent fromconsideration of the man-' ner}'in .which theoil undergoing treatment ishandled in, the apparatus, -The oil while passing in a sinuous mannerover the several reaction trays astasee ofa typicalccommercialaisizeapparatus? described is progressively suhjecteds'toithe influence of andintimatelyccontactedby every great number of jets. ofairissuingfronrtheclosing spaced slotson thelower edges ot the:bubblemaps Thus, the. eifect. in the. apparatusdsrepeatedly: to; mix theoxygen-supplying and? hydrating media with the oil stream in the severakreactionatraysofzthe apparatus. Such mixture. is; made; as; has beenshown, in a manner-:torefiecteaihigh order-offintimacy. The; isin..f.ormi ofibubbles; although the bubblestarevery small; and thewater, which may hold in solutiomaxr additionaltoxygem supplyingorcatalyzing: reagentis: mixed. intimately with the oilindropletaofrsmall; dimension by the actionof theair;

The eiiectiveness: of. the;v procedure thus depends upontherepetltiveitreatment;oiffthe oiliin the several reaction: trays; overwhich'i-t successively passes. limited proportion, of the. oil.molecules effectively into contact with available oxygen: atoms andwater molecules in eachrzone or treatment. during the progress of" theoil throughthereactor, is. effective. because the. oil. in-zrelatively"small volumn is repeatedly: subjected to hydroxylating media underhydroxylatingconditions; My preferred practice, insofar asthisapparatusflisiconcerned, is to conduct; the process: to eflectthroughout the body ofthezoil at least'substantially completehydroxylatlon of" the double bonds at the 1'2 -13 -position= inthemolecules of linoleic acid glycerid'e and at-the 15' -1'6"position inthe molecules of linolenic acid glycerlde.

It is not difii'cult toconductthehydroxylation step inapparatus of'this:sortiin a-manner toobtain the result above indicated; because thetendency so to function'is inherent. A primerequisite is that thewater-"supply be adequate, with respect toefiiciency, fully to hydratethe epoxide addition as it is made; Thus the temperature being withinthe approximate range of about 130 F. to 250 F., inthe:presencexof-"an:abundance of water, it is possible-Itohydroxylatethe-unsaturate carbon atoms ofthe-oil moleculesapproximatelyto the maximum ,extentawithout substantial formation of permanentoxidation-or objectionable rin compounds. If in beginning a run, samplesshow an undueproportion affixed oxidation products, the volume ofwatersupplied is increased, and if the-condition persists thetemperature is reduced toadegree-sufii'cient'to avoid suchcontamination; In the apparatus under consideration, the preferred timeof treatinent depends upon the-rate at which the oil is supplied. Thiswill, of course, vary withspecific'apparatus designs, individual oil,and the-other" conditions of the process. A preferred procedure-is totest a sample for its order-ofhydroxylation soon after the beginningof arun and'accord'ingly'toadjust the several" operatingvariables;

The oil which hasbeen subjected to the-bydroxylating treatment. andwhich lies as an upper layer on thewater-in the baseofythereactori; iscontinuously withdrawn at anadjusted rate' of discharge by-means ofa'pump 38-, and an; oil level controller 39, operable by way" of pumpflowregulating valve 40" to maintain the upper surface of the oil in thebase of 'thereactor'at an approximately constant'level.

Desira-bly; drawofl line 41; which leadsfr'om'the interior of thereactor-3 to-the pump-38% is provided with a valveddrawofi'connection'll aby which test'samplesreadily may be taken oftfrom time to time.

Suchtreatment, whichrbrings a Oil drawn ofi by pump 38 is delivered toapparatuszfor conducting the second, or dehydrating, step of the processby way of supply line 42. Desirably, supply line 42 passes by way of anoil heater 43: and de-aerator 44, in order to remove fromv the oil anyentrained or dissolved air, loosely-bound oxygen, or moisture, whichwould cause-excessive foaming and promote the formationof undesiredcompounds in the dehydroxylation treatment. Thus, oil passing by way ofsupply'line 42 is firstheated, as in the heater 43, and isthen deliveredto tie-aerating vessel 44, which is maintained under suitably reducedpressure, by which. entrained or dissolved air and moisture are removedin the form of vapor by way of vapor outlet connection 45. The reach ofthe discharge-line 42-1eading from de-aerator 44 is provided with a pump46 leading by way of connection 41:, to a-heat-exchanging element 43incondensi-ve dehydroxylation reactor 50. From heatexchanging structure43, supply line 49 leads through other preparatory apparatus elements toinlet 51- adjacent the top of the reactor.

The-preparatoryapparatus elements, as shown, comprise a catalyst-mixingchamber 52, in which the oil is intimately mixed with suitablecondensi-ve dehydration and hydrolysis-promoting catalysts from a supplytank 53, and proportioning catalyst-feed device 54 of commonconstruction. As shown, catalyst supply tank 53 is provided" withagitating means 53a by which the catalyst may be mixed-with a smallportion of oil, which-desirably is identical with the main body of-"oilsubjected to treatment. Between catalyst mixer 52 and inlet connection51, supply line 49 leads-through an oil heater 55in which theflowing'stream ofoil is brought initially to a temperature which atleast approximates that of the condensive dehydration reaction towhichit is to be subjected.

Condensivedehydroxylation reactor 50 desirably is constructed throughoutof a metal capable of resisting thecorrosive action of the materialsintroduced into-it or produced in conducting the process; Its shell is acylindrical columnar body of adequate cross-sectional area to providefor thesevera-l effects to be created in it, and is of a height adequateto provide a relatively great length of travel of oil passed downwardlythrough it and subjected to the condensation reaction in' its-passage.Within reactor 50 and of a length approximating the height of thereactor shell, there is -a tubular element divided vertically'intoanupper heated: reaction section 56, anda lower cooling section 51, whichforms part of-the-heat-exchanger 48, by which the incoming oil isheatedand by which the temperature ofoil' treated in the reactor is rapidlylowered.

Pre-heated' oil entering reactor 50 by way of inlet connection 51-, isfirst received by a separatingvaporizer 58; in which any fatty acids, orother volatiles which may be carried by the heated oil flash-vaporizeunder the pressure conditions existing interiorly of the reactor, andpass by way of vapor outlet 59-to suitable condensing andcollecting-meansnot shown. It may be explained thatthe-interior ofreactor 50 surrounding the tubular structure 56-: and 51, desirably ismaintainedata reduced" pressure, for example under a pressure of Ste 5mm. of mercury, by suitable vacuum-creating. means, not shown. The oilin substantially liquid'form passes from vaporizer 58 by way of aconnection 60, to an oil distributor Glatth'etopof' reactortube 56; fromwhich it is passedoutwardly'by way of. a number of narrow,

or for storage.

. be about .065" and even less in thickness. The

oil film travels downwardly over reactor tube 56 rapidly under gravity,as for example, at a speed of to lineal feet per second, the speed atwhich the oil in such fllm travels depending somewhat upon the viscosityof the oil and the effect of vapor formed by the reactions which takeplace in the oil film.

Any suitable agency such as hot vapors, hot circulatin fluids, orelectricity for heating reactor tube 56 to the relatively hightemperature required for the flash condensive reaction may be used,preferred heating means being shown in Fig. lb and in Figs. IV and V ofthe drawings. As shown therein, reactor tube 56 is electrically heatedby means of electric current which is supplied by way of transformer 63and electrical connections 64, 64a. Transformer 63 receives current froma line 65 leading to any suitable current source, by way of automaticcontrol switch 66, operable under the influence of a thermostaticregulator 61 and which has electrical connections 60 to transformer 63and connection 69 with a thermocouple 10, which lastnamed elementextends through the reactor shell into operative relation with theheated surface of reactor tube 56.

Electrical connection [4 between low-resistance tube H andhigh-resistance tube 15, together with its insulator, is engaged in aliquidtight partition l6 arranged at the junction between heated reactortube 56 and lower cooling tube 51. c I

The film of oil, passing rapidly down the surface of reaction tube 56 israised quickly to a relatively high reaction temperature lying withinthe approximate range of 500 F. to 700 F., such as a temperature ofabout 550 F; and continuing downwardly over the surface of cooling tube51, still in the form of a thin, rapidly flowing stream, is cooledquickly to a temperature below that which would produce in itsubstantial heat polymerization. For example, it is rapidly cooled to atemperature of about 275 F., or lower, by heat exchange with the coolerstream of oil flowing upwardly in annular'space 81 in direct contactwith the inner surface of cooling tube 51. The treated oil thus cooledcollects in space 89 at the base of the dehydroxylation reactor, and iscontinuously delivered from it by way of a discharge connection 90 forfurther treatment,

I have found that there is a substantial difference in the temperatureat which the hydroxyl groups in difierent positions in the carbon chainreact or condense with adjacent hydrogen atoms, the hydroxyl groups atthe remote carbon position reacting at a substantially lower temperaturethan those groups nearer the glycerol group in the oil molecule. Thisdifference in reaction temperature is quite substantial, and may amountto as much as 50 F. or more. While flash dehydration is desired, if thecondensive reaction should take place instantaneously throughout allregions of each of the hydroxylated oil molecules, upon contact in theupper region of the reactor tube, the immediate evolution of substantialamounts of water produced by the condensive reaction would result inviolent ebullition and oil might thus be thrown mechanicallyflOmthe'surface of the reaction tube.

In my condensive dehydroxylation step, the condensation reaction is ineffect a flash reaction, inasmuch as it usually takes place withinasperiod of a fewv seconds, at a temperature of from about 500 F-. to700 F., rather than in a period in the order of three to four hours attemperatures from about 450 F. to 540 F., when condensivedehydroxylation is conducted in ac: cordance with a batch procedure.That is, in the progress of a thin film of the oil downwardly on. thesurface of, a reactor, such as the surface of the. reactor tube 56 ofthe dehydroxylation apparatus shown, the oil is subjected to condensivereaction-temperatures so high that dehydroxylation is:substantiallyacompletebefore it is cooled,

as by passing over the cooling surface, such as is provided by thecooling tube 51 of the apparatus shown. As indicated above, it isdesirable, however, that the-tcondensive flash reaction should not .beso wholly instantaneous as to produce violent mechanical effects in thefilm of oil sub- .iected to treatment. Thus, I preferto supply 011 whichhas been pre-heated, as by its use in heatexchange and subsequentheating in an oil heater, to a temperature which is at least 50 belowthe maximum temperatureto which it is to be brought in the reactor. Forexample, Iprefer to supply the oil at a temperature no higher than fromabout 450 F. to 500 F., and to bring it during its brief period ofcontact with the re actortube to its maximum, or flash, reactiontemperatureof at least 500 F., so that the zone of the condensivereaction comprises substantially theentire length of reaction tube 56.

.Bythe term fflash condensive dehydration, I mean a condensivedehydroxylation reaction in which the oil is subjected for a very shortperiod notsubstantially exceeding 1 minute to elevated temperature fromabout 500 F. upward and below a temperature at which heat-decompositionof the ,oil will take place during the period of the treatment. I havefound that such flash dehydration should be performed upon an attentuatebody of the hydroxylated oil, such as the thin, circular stream, orfilm, of oil which the condensive dehydroxylator above described isorganized to present.

The rapid cooling should in each instance bring the oil to a temperaturebelow that at which the viscosity of the specific dehydrated oil issubstantially increased by heat reaction.

By operating under subatmospheric pressure, as by maintaining a pressureof 5 mm. of mercury or less within the reactor, the flowing stream, orfilm; of reacting oil is maintained in substantially anhydrous conditionby the continuous removalof water produced by the condensive reactionsubstantially as it is formed. The prompt removal of the water evolvedby the condensive reaction from the flowing film of oil and the use ofrelatively high reacting temperature, provide conditions under which therate and the extent of the dehydrating reaction may approach themaximum. Water being an end product of the reaction, tends strongly toinhibit its progress. Instantaneous removalof water, and thepresentation of the oil in a thin stream, or film, greatly acceleratesthe condensive reaction at the temperatures to which the oil issubjected. Because of the very brief period of time during which the oilis subjected to high temperature ineffecting the condensation reaction,such high temperature may be utilized Without higher temperatures withinthe given range, the

use of condensive dehydrating-promoting catalysts is not important,and-that in the treatment of many oils the condensive dehydroxylationmay be completed to anadequate degree in the substantial absence of suchcatalysts.

It may be stated that my flashdehydrating effects approximately completedehydroxylation with the production of ancil having the desired highorder of conjugate unsaturation, without involvin as an incident to suchreactionheatpolymerization of the oil, which the further treatment towhich the oil is subjected or the use to which the oil is to be putmight render objectionable.

An exemplary form of hydroxylation reactor purposed particularly forhighly selective hydroxylation oi the oil, is shown in Fig. VII of thedrawings. This reactor, the shell of which is I'iesignated by referencenumeral 95,.re'ceives oil for treatment through line 96 undertheinfluence of feed pump 9-1, and by way of flow indicator 98, and oilheater 99. Oxygen-supplying gas, for example air, is supplied insuitable quantity and under suitable pressure by means of air blowerI00, flow indicator IIlI, air heater I02, and by way of line I63, totheinterior' of reactor shell 95. Steam, or hot water, is supplied bywayof connection I04, and flow indicator I to'a'irsteam mixer I06 insuitable quantity to efiect hydroxylation of the epoxide addition formedby reaction between unsaturate carbon atoms in the oil and oxygensupplied by the" air. Both oil supply line 96' and air-steam supply lineI03 connect with an atomizer IB 'Lby which the oil is discharged'intothe interior of the reactor in the form of a fine mist, or spray,intimately commingled with the oxygen-supplying gas, and with thehydrating medium, such as steam or water vapor. By thus eiiecting highlyintimate'an'd immediate contact between the'oil and'the oxidizing andhydrating media, there is asub'stantially instantaneous reaction, orsequence of reactions, by which hydroxylation' of highly selective sortis effected.

Desirabl-y, the mixture of air and'steam is supplied to atomizing deviceI07! at" a suitable hydroxylation temperature within the range abovenoted, such as atemperature of 175 F., and desirably, the oil for"treatment-is supplied to the atomizer at a similar temperature. thispurpose, oil heater 99 isprovided with a heating medium, such as steam,by wayof a connection99a, supplied under the control of a temperatureregulator 99b. Similarly, air heater I 02 desirably is supplied withpre-heating' steam by way of a connection I020, under-the control of atemperature regulator I021): Assuming, for example, that oil issuppliedto the-reactor at a rate of 1000 lbs. per hour, I have found an airsupply of 225 cubic feet per. minute. adequate to effect epoxideaddition to selected unsaturated carbon atoms in the oil moleculewithout substantial formation of fixed oxidation compounds therein,providing that the steam, or other source of hydrating water at-adesirably high temperature, is also supplied in a quantitysufiicientinstantaneously to hydrate and thus-t0 make hydroxyl additionto the unsaturate carbon atoms as epoxide formation is efiectecb If'itis-desired For '16 to ac'cel'erate': epoxid'e formation, and consequent-1y to. accelerate hydroxylation, a minute amount or suitableoxidation-promoting catalyst,

such for example as av compound of cobalt or the likei prefera'bly inoil soluble form, may be supplied-with the oil. Preferably the reactionchamber-' is maintained ata suitably reduced pressure,.such as apressure of from 20 to 25 in. of: mercury; in order to preventcondensation of the hydrating'steama -Reduced pressure has anotheradvantage in that because of expansion the volume of the air is greaterthan at atmosphere pressure, thus. providing greater contact eidciencybetween the oxidizing air and hydrating steam-and the minutely dividedoil particles in the form of mistproduccd by the atomizer.

Briefly to consider the organization of the hydroxylation reactor, aninner shell Hi8, concentric with the outer shell 95, desirably issupported withinthe reactor shell by means of spiders to provide anannular space III], for the-escape of: unreacted air and other vaporsirom tne reactor-by way of vapor outlet I I I. An oil level controldevice I I2 is connected in the lowersregion'of the reactor, and isoperable by \vay'of an oil discharge pump I I3, and flowregulating-valve H 5, to maintain the oil within the reactor atasubstantiallyconstant level. Because epoxide'for-rnation is a-reactionwhich is highly exothermic, cooling coil I I5 desirably is provided toestablish heat-abstracting conditions in the interior of the reactor.

In operation, the fine oil particles under the influence of gravity andbecause of the velocity imparted to them'by atomizer I07, fall to thelower part of the reactor. ated oil is retained for a sufficient periodof time under the influence of oil level control deice 5 I2 to effectgravity separation between the oil and any water which may be mixed withit. The oil from the oil stratum H6 is constantly removed by means ofpump II3, and passes by way of discharge line 32a to the dehydrogenatingreactor. Separated water is drawn oil by valved connection I I? tomaintain an approximately constant. level of the oil-water interface.

Excess and oxygen-depleted air, together with steam and any othervaporous products of the reaction, escape by way of annular space III!to vapor outlet II I, passing on their way through oil entrainmentseparating louvres I I8 which act substantially to remove entrained oilparticles from the discharged vapors. It is to be understood that oilpassing by way of line 42a to the condensive dehydrogenation reactor 50as with the form of hydroxylating apparatus previously discussed,desirably passes through a similar oil heater and de-aerator to removeany entrained or dissolved air, loosely-bound oxygen, or moisture fromthe oil; and that the heating and other steps preparatory to delivery ofthe oil to the de hydrogenation reactor are similarly conducted.

I have found when using the above described form of flash hydroxylationreactor, because of better contact eihciency between the oil and theoxidizing and hydrating media, the brief or practically instantaneoustime of the exposure of the oil to the treatment, and the more exactregulation of the variables controlling the reaction, that substantiallygreater reacting temperatures may be utilized in the treatment withoutsubstantial formation of fixed oxidation and other objectionable ringcompounds in the oil, than when treating the oil by other methodsinvolving relativelylonger times of treatment There the hydroxylwhichoffer greater opportunity for the formation of such objectionablecompounds, thus not only increasing the rate of 'productionmany times;but also producing a more uniformly treated product. The flashhydroxylation may be utilized to effect a mild and but partialhydroxylation to the oil by selective diminution of the operatingvariables such as air, temperature, and oxidation catalyst, or to effecta more intense hydroxylation of the oil by selective intensificationof'those variables.

I shall nowgive specific exemplification of runs which have beenconducted in accordance with the procedure of my method and in apparatusas herein shown and described, It is tobe' understood that suchexemplification is in nowise restrictive,'but that it will be subject towide varia-' tion in response to a number of conditions. Even differentbatches of the same sort of oil preferentially ask accommodation in the'conditions of their treatment, and minor variations in the structure ofthe apparatus also cause variations in the conditions most to bepreferred. The example given immediately below is to be understood asconducted on linseed oil as the starting material, such oil being of acommercial quality which has been subjected to the usual refiningtreatment for'the removal of gum, mucilage, and other colloidal andsuspended impurities, and for the removal of excess free fatty acids.

The example is to be considered as illustrating a treatment in thehydroxylation apparatus shown'in Fig. Id of the drawings, and in thedehydroxylation apparatus shown'in Fig. 1b of the drawings, or inclosely analogous apparatus. It will be noted that in the example all ofthe hydrating water is supplied in the form of steam. This is mypreferred procedure for several reasons. In utilizing steam, thehydrating medium being in the form of vapor, may be initially commingledwith the air which supplies" oxygen for epoxidation, and being in theform of vapor is more uniformly and intimately commingled. with the airthan is possible when utilizing'water in liquid state.- Thus, in the useof steam, awater molecule for hydration is associated so directly withan oxygen molecule of the air that the conditions favor simultaneouscontact of both with the oil molecule, to 'cause instantaneous hydrationof the epoxide as it is formed; Such 1 mechanism serves to inhibit theformation of permanent oxidation products, and renders hydroxylation ofthe oil molecules more selective. Additionally, the use of steamavoidsthe tendency toward emulsification which is present when water inliquid state is used as the hydrating medium. I Y

Emamplei In accordance with this procedure, linseed oil for treatmentwas supplied to the hydroxylatingreactor of Fig. Ia .in the mannerdescribed in the description of that apparatus, at areacting temperatureof about 165 F., and at the rate of about 1000 lbs. per hour. Air foroxidation, preheated to a temperature of about165f" F., was supplied ata rate of about 275 cubic feet per minute. Steam for hydration wassupplied at a rate of about 225 lbs. per, hour, being in accordance withthe disclosure of the reactor .to which reference is made, commingledwith the air to pass upwardly with it through the several reaction traysof the apparatus; A reduced pressure of about 20 inches of mercury wasmaintained withinthe reactor during the;

' free of hydroxyl and other 18 process, substantially to preventcondensation of the steam at the reaction temperature. The oil subjectedto treatment passed downwardly through the reactor in the mannerdescribed in connection with the apparatus; and with the size andarrangement of apparatus used, the oil was subjected to treatment for aperiod of about 30 minutes'during its progress through the reactor.

Treatment under the conditions given resulted in the selective additionof hydroxyl groups to the remote pairs of unsaturate carbon atoms of thelinolenic and linoleic acid glycerides of the oil composition withoutsubstantial oxidation, or hydroxyl group addition, to those unsaturatecarbon atoms of the linolenic, linoleic, or oleic acid glycerides lyingnext toward the glycerol radical of the glycerides. In terms of hydroxylvalue, the treated oil showed a hydroxyl value of about 210 as comparedwith an initial hydroxyl value of about 4.

The linseed oil hydroxylated as above, in preparation for treatment in adehydroxylator of the sort shown in Fig. Ib, was subjected to adeaerating temperature and reduced pressure of about 3 to 5 mm. ofmercury, and was raised from a, temperature of about 180 F. to about 360F. with addition of a suitable dehydrating catalyst, which specificallyconsisted of about 0.5% sodium acid sulphate. The oil was then heated toa temperature of about 475 F. and free fatty acids and other volatilecompounds were flashed off. 1

The oil thuspreparedfor condensive dehydroxylation wasthen treated inaccordance with the, procedure given in the description of the apparatusof Fig. lb. As closely as could be estimated, theoil was brought in athin film and under a reduced pressure of about 3 to 5 mm. of mercury toa temperature progressively increased during a period of about 5 secondsto a maximum of about 610 F., and was immediately cooled to atemperature of about 300 F. As will have been apparent from thediscussion associated with the description of the condensivedehydroxylating apparatus, this flash condensive dehydrating primarilyis rendered possible by the fact that the oil'is subjected to treatmentin a thin film, so that within a short period of time it may be raisedto a high temperature and the temperature reduced to below: a point inwhich heat-polymerization will occur in the oil. During the treatmentthe dehydroxylating reactor was maintained under a reduced pressure ofabout 3 to 5 mm. of mercury, and the water evolvedby the condensivereaction was instantaneously removed from the thin rapidly flowingstream-pf oil. Likewise relatively volatile materials in the oil, suchas fatty acids, reduced glycerides, and other volatile non-dryingcontaminates, such as aldehydes, ketones, and oil decompositioncompounds which may have resulted from the prior'treatment to the oilwere vaporized and eliminatedfrom the flowing stream of the oil. Thetreated oil was thus substantially addition groups, and of saturated andother non-drying contaminates.

The oil subjected to the had been converted from, an oil having theusual drying properties of linseed oil to one having a high degree ofconjugate unsaturation, with high heat-reactivity and improvedfilm-forming properties. The oil had been converted from one initiallyrequiring about minutes to gel under standard gelation test conditions,to one that will gel under the same conditions in about 15 minforegoingtreatment utes. The oil also had a desirably low viscosity, its increasein viscosity by the above described treatment being from an initial ofabout 4 poises to about 18 poises, and because of the minimizedformation of fixed oxidation products during the hydroxylating reactionthe oil had a desirable light color. Because of the distilling orstripping action at high temperature and reduced pressure, the oil wassubstantially neutral, having a F. F. A. of about 0.15%.

Example 2 A mixed oil, consisting 50% of commercial refined linseed oilas in Example 1 and 50% of refined desaturated soya bean oil, wassubjected to treatment in apparatus combining a hydroxylator as in Ia.with a condensive dehydroxylator as in Fig. Ib. The conditions weresubstantially identical with those given above in Example 1. By thistreatment, the mixed oil was converted from one requiring about 60minutes to gel under standard gelation test conditions, to one thatgelled under the same conditions in about to 12 minutes. The viscosityof the treated oil was about 10 noises.

It may be noted that in treating soya bean oil and like oils having alarge proportional content of saturates and semi-saturates it isdesirable, as hereinafter more fully explained, to desaturate the oilbefore treatment.

Example 3 A so a bean oil which had been refined, as was the linseed oilof Example 1, but which. contained its total initial content of theglycerides of saturate fatty acids and oleic acid glyceride, wassubjected to treatment in a hydroxvlation reactor such as is shown inFig. Ia and a condensive dehvdroxylator such as is shown in Fig. 1b. Intreating this oil, hydroxylation was carried to a point of substantialcom letion rather than selectively performed as in the treatment of thelinseed oil and the mixed oil of Examples 1 and 2. In so doing, theconditions of the hydroxylation reaction were intensified. Assuming thatthe oil was fed to the reactor at a rate of about 1000 lbs. per hour,air heated to about 190 F. was supplied at a rate of about 325 cubicfeet per minute. Hydrating steam was supplied at a rate of about 350lbs. per hour in order to give assurance of an abundance of hydratingmedium.

The oil itself was pre-heated to the same temperature as the air, namelyto about 190 F.. in order to provide a reaction temperature in thatorder. The reactor was maintained at a reduced pressure of about inchesof mercury in order to prevent condensation of the steam.

The untreated soya bean oil required about 220 minutes to gel understandard gelation test conditions. and the treated oil gelled under thesame conditions in about 22 minutes.

Example 4 Linseed oil of the sort and in the condition described wassubjected to hydroxylation in a hy- I minute and was atomized with steamsupplied at a rate of about 400 lbs. per hour. The interior of thereactor was maintained at a reduced pressure of about 20 inches ofmercury.

The oil treated by this procedure corresponded very closely to the oiltreated by the procedure of Example 1.

It is to be understood that in all of Examples 2, 3 and 4, thecondensive dehydroxylation operation and the steps by which thehydroxylated oil was prepared for that stage of the process wereidentical with those described in Example 1.

The foregoing examples point the direction in which adjustment may bemade in the several 1 variables involved in the process, in accordancewith the properties of the starting oil, the desired properties of theproduct oil, and the influence of the apparatus used upon preferentialprocedure.

Returning to the chemical mechanism involved in my novel treatment ofdrying oil, it will be considered that linolenic acid glyceride andlneolio g yceride the glycerides acted upon in the treatment. It will beassumed, also, that the treatment has been a selective one in whichhydroxylation followed by condensive dehydroxylation has been effectedat a desired point of attack in the acid radical of the oil molecule.The following formulae will illustrate the change effected in the acidradical of the glyceride, the glycerol radical being omitted for thesake of simplicity.

The linolenic acid radical (313001802) may be represented as follows:

Formula A H H C COOH Observing the formula, it is seen that the carbonatoms in the 9-10 positions are linked with a double bond, as are alsothe carbon atoms in the 12-13 positions and in the 15-16 positions.

If, then, hydroxyl addition is made at both the carbon atoms in the15-16 positions we obtain Formula B, as follows:

Formula B (H32C1s04) Formula B shows the selectively hydroxylated acidradical before condensive dehydroxylation, with both the carbon atoms inthe 15-16 positions saturated by addition of an OH group.

Formula C shows the acid radical after condensive dehydroxylation asfollows:

Formula C (H2sC1sO2) urznuuuuuns HHHHHHEHHH H1 In this modification ofthe structure, a hydrogen atom in the 14 carbon position and a hydrogenatom in the 17 carbon position have been involved in a condensivereaction with adjacent hydroxyl groups b which two molecules of waterare formed. The removal of those hydrogen atoms has resulted in theformation of double bonds between the 16 position carbon and the 17position carbon, and between the 14 and the 15 position carbons. Thedouble bond linking the carbons in the 13 and the 12 positions hasremained unaltere'cL'as has also the isolated double bond between thecarbons in the 9-10 positions.

From the above, it will be seen that the result is to produce a novel'glyceride, in which the acid radical has three double bonds inconjugate relation, in addition to one initial double bond which isstill in non-conjugate position. Also, it will be seen that at eachoriginal pair of unsaturate carbon atoms the hydrogen atoms adjacentboth the carbons hav'e gone to form the two molecules of water,' so thatdouble bonds have been introduced in'both directions from the doublebond originally present.

The effect is analogous in acid glycerides. The formula for linoleicacid is as follows:

Formula D (HszCmQz) unneran It will be seen in this formula that thelinoleic acid radical has two isolated double bonds, one between thecarbons in the 9-10 position and the other between the carbons in the12-13 position. It has been explainedthat *hydroxylation is effected atthe 12-13 carbons'morereadily than at the carbons in the 9-10 position.The linoleic acid glyceride being selectively hydroxylated, the

structure will then appear as follows;

m nu

This effect is to add hydroxylfgroups at the carbon atoms in the 12 and13 positions, which upon condensive dehydroxylation, as shown above,involves the hydrogen atoms in the '11 and 14 carbon positions, themodified structure derived from the linoleic acid radical of the oilmolecule then will have double bonds in the 9-10, 11-12, and 13-14positions in accordance with the following formula:

- Formula F (Hacmoz) Formula G (HaoCmOz) g H o E If we assume that theoil treated is linseed oil,

moms

moral:

mobile consisting 24% of'linolenic acid.'glyceride,.and

62% linoleic acid glyceride;.,with, 5% oleic acid glyceride, and 9% ofthe glycerides of saturated fatty acids, it will be seen that thetreatedj'oil has a total reactivity corresponding very closely to thatOf China-wood oil, although the points the case of linoleic"hydroxylation be restricted to the remote unsaturate carbon atoms in thecarbon chains 'of the molecules attacked) and then subjected tocondensive dehydroxylation, the resultant product derived from naturalsoya bean oil would consist about 50% of a glyceride respondingsubstantially to the formula for eleostearic acidglyceride, about 6% ofa glyceride containing threeconjugate double bonds, and one nonconjugate"double bond, about glyceride, and may have about 14% glycerides ofsaturated fatty acids.

of unchanged Such product oil is a good drying oil. Further to improve 1the properties of such product oil, the content of the glycerides ofsaturated fatty acids and of unchanged oleic acid g'lycerides desirablymay be removed by solvent extraction, in accordance with any of thevarious solvents and procedures which are well-known for the separationof saturates and semi-saturates from the unsaturate fatty'acidglycerides; and with any of the wellknown suitable solvents for thatpurpose, such as those of the class comprising actone, ketones, andthe-higher molecular weight alcohols. It is to be understood thatlinseed oil and other oils treated in accordance with my methodsimilarly may be subjected to solvent extraction, in the event theirnon-reactive content is too great to give them the ability to form filmsof a desired hardness. It is also to be understood that such oils may besubjected to solvent extraction substantially to remove the saturatednon-drying components from the oil prior to subjecting it t to treatmentand the concentrated unsaturated components utilized as the starting myproduct oil.

An instance in which selectivity is of particularly great importance ispresented by the fish oils, which contain in addition to a moderatecontent of linoleic acid 'glyceride and. linolenic material for acidglyceride, a moderate content of the highly unsaturate and non-conjugateglycerides,'such as clupanadonic acid, containing more than 18 and up to26 carbon atoms in their carbon chain, and initially having from c to 6points of unsaturation in their structure. 1

I have found in treating such oils to obtain what is in practical effecta flash hydroxylation'; as in the'manner which I have described withreference to a reactor of the type shown. in Fig. VII of the drawings,that in the hydroxylation treatment the addition of hydroxyl groups tothe linoleic acid and linolenic acid radicals proceeds proportionallywith the addition of hydroxyl groups in the fish oil acid radicals. Theincreased unsa uration and conjugation in those radicals is bal- 'anced'sufficiently by the greater length of the carbon chain and theproportionally greater molecular weight as compared with linoleic andlinolenic acids, to give an oil of approximately uniform hydroxylation.

It may be stated that my invention resides primarily in treating adrying oil having a substantial content ofthose unsaturate iattyacidradiof oleic acid calswhich containiatleast l8carbon atoms,-andsort towhich the treatment is directed are hydroxylated either fully or in lessthan maximum order, with consequent control of the extent to whichtheirpolymerizing reactivity is increased; and resides incondensively:dehydroxylating by means of aflash' dehydration whichefiectively dehydroxylates the hydroxylated oil, without decomposing theoil or unduly increasing its viscosity.-.

To the extent that the starting oil consists. of reactive glycerides,that is glycerides of fatty acids having at least 1-8 carbon atoms'inthe carbon chain and at least two pairs of carbon atoms linked by doublebonds, the oil is increased in iodinevalue from a very substantialpercentage increase to an increase of more than 100%. The increase inunsaturation, or iodine value, is inevitably accompanied by conjugation,because each double bond-which'origina lly links two carbonzatoms isreplaced by two double bonds each linking one-of the originallyunsaturate carbon atoms with another adjacent carbon atom.

Considering the two commercial drying oils considered above, namelylinseed oil and soya bean oil, it-has been explained that the linseedoil has an initial iodine value of about 180 and the soya bean-oil hasan iodine valueofabout 140. By selectively subjecting these oils totreatment. in accordance :with my method under controlledconditions, Iam able to increase the iodine value of the linseed (with conjugation)to from about 200 to about 350. Similarly, I am able-to increase theiodine value of the soya bean oil (with conjugation) to from about 150to about 250.

By virtue of an hydroxylation treatment which is effec-ti-verapidly toproduce epoxide formation with substantially simultaneous hydration, theoil is approximately free of permanent oxidation and other objectionablecompounds. By virtue of condensive dehydration eifectively performed theinitial viscosity of the product oil is not undesirably increased.

My drying oil product thus is an improved oil resultant from an oilhaving a substantial initial content of non-conjugate unsaturatereactives,

in which unsaturation has been increased with an increase in conjugationwhich matches the increase in unsaturation. That is, increasedunsaturation is efiective proportionally to product conjugation. Theposition of the unsaturation and of the conjugation in the molecules ofthe treated oil is determinate.

The foregoing disclosure of my invention has been made full anddetailed, in order that the invention may be fully understood and thatfull I;

benefit may be derived from it. As above indicated, however, it is to betaken that such detail disclosure is descriptive and not restrictive,and that the scope of my invention is to be limited only by thedefinition of my invention as contained in the appended claims.

I claim as my invention:

1. The method of improving the heat reactivity and film formingproperties of non-conjugate glyceride oils containing a substantial.proportion of components havingtwo or more pairs ofunsaturatedatomsin'their carbon chain, which com prises subjecting,-.aconfined continuously flow-- ing stream 01: the oil divided into aplurality of successive shallow pools while passing down-- wardlythrough a treating vessel; to selective hydroxylation by intensivelyblowing said pools in the presence :of a hydroxylating' catalyst withupwardly flowing stream of oxygen ccntz ring gas, intimately mixed withhydrating steamin amount sufficiently greater than the theoreticalamount required to hydrate the epoxy groups to insure the hydrationofall of the epoxy groups:-

selectivelyadded thereto bysaid blowing at a selective epoxidationreaction temperature wit the range of F. to 250 F. for approximately 30minutes, sufiicientto selectively add hydroxyl groups to the remotepairs of unsaturated carbon atoms of said unsaturated components withoutsubstantial oxydative polymerization thereof or oxygenation of the 9-10unsaturated carbon atoms present -in=said.oil composition, then quick-1yremoving such hydroxylated oil from the zone of oxidation, removingfree-waterand air therefrom and subjecting-the oil toflash-dehydrowlation by quickly heating athin rapidly flowing stream at.a .reducedpressurein the presence of a dehydrating catalyst atv adeterminate iiasll rlehydrating temperature within the range o1" 500 to700 F. for abrief, substantially non-thermal polymerizing period of timeabout one minute or less correlated to said dehydrating temperature,effective to produce a substantially non-oxidized, non-polymerizedconjugate type drying oil product containing a substantial proportion ofglycerides having one more double bond than the corr spondingunsaturated components of the said starting oil from which they werederived.

2. The method as set forthin claim 1 wherein said glyceride-oils includelinolenic glyceride and said epox-idation temperature is within therange of 130 F. to Frand wherein hydroxyl groups are selectively addedat the 15-16 carbon positions of said linolenic'glyceride, to produce anoil product-having a substantialproportion of glycerides having doublebondsat its 9-10, 12-13, 14-15 and 16-17 carbon positions.

3. The method as set forth in claim 1 wherein said glyceride oilsinclude linoleic glyceride and said epoxidation temperature is withinthe range of 200 F. to 250 F. and wherein hydroxyl groups areselectively added at the 12-13 carbon positions of said linoleicglyceride to produce an oil product having a substantial proportion ofglycerides having double bonds at its 9-10, 11-12, 13-14 carbonpositions.

4. The method of improving the drying prop erties of linseed oil as setforth in claim 2.

5. The method of improving the drying properties of soy bean oil as setforth in claim 3.

ROBERT A. CARLETONJ REFERENCES CITED The following references areoi'record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,565,249 Berry Dec. 15, 19252,083,220 DeGroote June 8, 1937 2,194,250 Turek Mar. 19, 1940 2,278,425Colbeth. Apr. 7, 1942 2,308,152 Boone Jan. 12, 1943 2,317,362 ColbethApr- 27, 1943 2,361,793 Porter an; 1. Oct. 31, 1944

1. THE METHOD OF IMPROVING THE HEAT REACTIVITY AND FILM FORMINGPROPERTIES OF NON-CONJUGATE GLYCERIDE OILS CONTAINING A SUBSTANTIALPROPORTION OF COMPONENTS HAVING TWO OR MORE PAIRS OF UNSATURATED ATOMSIN THEIR CARBON CHAIN, WHICH COMPRISES SUBJECTING, A CONFINEDCONTINUOUSLY FLOWING STREAM OF THE OIL DIVIDED INTO A PLURALITY OFSUCCESSIVE SHALLOW POOLS WHILE PASSING DOWNWARDLY THROUGH A TREATINGVESSEL, TO SELECTIVE HYDROXYLATION BY INTENSIVELY BLOWING SAID POOLS INTHE PRESENCE OF A HYDROXYLATING CATALYST WITH AN UPWARDLY FLOWING STREAMOF OXYGEN CONTAINING GAS, INTIMATELY MIXED WITH HYDRATING STEAM INAMOUNT SUFFICIENTLY GREATER THAN THE THEORETICAL AMOUNT REQUIRED TOHYDRATE THE EPOXY GROUPS TO INSURE THE HYDRATION OF ALL OF THE EPOXYGROUPS SELECTIVELY ADDED THERETO BY SAID BLOWING AT A SELECTIVEEPOXIDATION REACTION TEMPERATURE WITHIN THE RANGE OF 130*F. TO 250*F.FOR APPROXIMATELY 30 MINUTES, SUFFICIENT TO SELECTIVELY ADD HYDROXYLGROUPS TO THE REMOTE PAIRS OF UNSATURATED CARBON ATOMS OF SAIDUNSATURATED COMPONENTS WITHOUT SUBSTANTIAL OXYDATIVE POLYMERIZATIONTHEREOF OR OXYGENATION OF THE 9-10 UNSATURATED CARBON ATOMS PRESENT INSAID OIL COMPOSITION, THEN QUICKLY REMOVING SUCH HYDROXYLATED OIL FROMTHE ZONE OF OXIDATION, REMOVING FREE WATER AND AIR THEREFROM ANDSUBJECTING THE OIL TO FLASH-DEHYDROXYLATION BY QUICKLY HEATING A THINRAPIDLY FLOWING STREAM AT A REDUCED PRESSURE IN THE PRESENCE OF ADEHYDRATING CATALYST AT A DETERMINATE FLASH DEHYDRATING TEMPERATUREWITHIN THE RANGE OF 500* F. TO 700*F. FOR A BRIEF, SUBSTANTIALLYNON-THERMAL POLYMERIZING PERIOD OF TIME ABOUT ONE MINUTE OR LESSCORRELATED TO SAID DEHYDRATING TEMPERATURE, EFFECTIVE TO PRODUCE ASUBSTANTIALLY NON-OXIDIZED, NON-POLYMERIZED CONJUGATE TYPE DRYING OILPRODUCT CONTAINING A SUBSTANTIAL PROPORTION OF GLYCERIDES HAVING ONEMORE DOUBLE BOND THAN THE CORRESPONDING UNSATURATED COMPONENTS OF THESAID STARTING OIL FROM WHICH THEY WERE DERIVED.